This might be a stupid question, but can someone answer the following scenario:

Lets say I happen to have a unique support on the battlefield, maybe Ghost.

I exhaust it and roll the die into my pool. On a subsequent turn I resolve the die and the die goes back onto the exhausted support.

I happen to have another Ghost in my hand and the resources to play it. If I play it, does the first one on the battlefield get discarded and the one I just played onto the battlefield come in at a ready state?

I realize that you can have (2) of the Ghosts in your deck, but one on the BF due to it being unique.

This came up in my Hera/Lando vehicles deck.

I couldn't find a ruling on this. I'm comparing this to Magic on how it treats Legendary cards, where if you have one in play and if you played another, the first one would go to the graveyard.

Any help or rules reference would be appreciated!

RRG page 3. You aren't even allowed to attempt to play the second copy of Ghost so the situation you are asking about can't occur.

You cannot play unique support / upgrades if you have already one in play with the same name

Got it! Thanks!

Skipped over that section in my read of the rules...

Here is the reference:

UNIQUENESS

Each card is either unique or non-unique. Unique cards are marked by a diamond (*) before their titles. All other cards are non-unique. A player cannot have more than one copy of a unique card in play at the same time. There cannot be more than one copy of a unique character on a team, and a player cannot play a unique support or unique upgrade if they already have another copy of that card in play. • The unique restriction applies to each player individually. Players can each have one copy of a unique card in play at the same time. • The unique restriction does not apply to dice. A player can have multiples of the same dice in play at the same time. • Characters with the same title but a different subtitle are still considered to be the same character for determining uniqueness. Example: A player cannot use Darth Vader, Sith Lord and Darth Vader, Dark Apprentice on the same team.